1. Field of the Invention
The invention is directed to the bearing of an electroacoustic miniature transducer having a housing and a sound passage opening arranged in the front side of the housing in a device, particularly in a hearing aid device. The invention is also directed to an electroacoustic miniature transducer.
2. Description of the Related Art
Electroacoustic miniature transducers are employed for converting electrical signals into acoustic signals as well as for converting acoustic signals into electrical signals. In numerous areas of employment such as, for example, in telephones or hearing aid devices, an acoustic signal is picked up by an acousto-electrical miniature transducer (microphone) and further-processed, and an acoustic signal is output by an electro-acoustic miniature transducer (earphone). In order to avoid feedback, the sound output by the earphone must be prevented from being picked up by the microphone. The degree of damping between earphone and microphone, namely, determines the maximally possible gain of the device. When, for example, in a hearing aid device, the acoustic pressure of the earphone proceeds into the microphone damped by 60 dB, feedback whistling will occur given a gain of around 60 dB.
In electroacoustic devices, a second, parasitic path of signal transmission exists in addition to the direct sound transmission from the earphone to the microphone. In addition to outputting sound directly via the air, the earphone can also output sound by vibrations of the earphone housing. Conversely, the microphone also picks up structure-borne sound via its housing. In the example of the hearing aid device, this parasitic path of sound transmission also reduces the damping between earphone and microphone and thus limits the maximally obtainable gain.
For increasing the damping, attempts are made to spatially separate the earphone and microphone as far as possible from one another. However, in, for example, hearing aid devices, this is only possible to a limited extent due to the desired miniaturization of the devices. For limiting the direct sound transmission through the air from the earphone to the microphone of a hearing aid device, the sound is conducted from the earphone into the auditory canal of the hearing aid user via a sound channel in which the auditory canal is sealed off from the outside by the hearing aid housing or an otoplastic.
German patent document DE 100 43 201 C1 discloses an electroacoustic miniature transducer having a housing and a sound passage opening that can also be employed in a hearing aid device. As second housing that surrounds the sound passage opening is present in addition to the housing of the miniature transducer. The miniature transducer is thereby fixed via a cylindrical connection piece in communication with a rubber house in the second housing.
German patent document DE 36 14 739 A1 discloses an elastic bearing for an earphone to be attached in a hearing aid in which an elastic bush is plugged onto a sound exit connection piece of the earphone and is buttoned into an opening of the hearing aid housing.